Epilepsy Stands Nearby: A Pilot CT Perfusion Study on Post-Stroke Non-Convulsive Status Epilepticus

BACKGROUND

To investigate the relevance of hyperperfusion on computerised perfusion imaging (CTP) in the emergency setting in people with non-convulsive status epilepticus (NCSE) and previous stroke, to derive relevant aspects on the epileptogenic focus and the network recruited for NCSE propagation.

METHODS

We enrolled consecutive adult patients with acute-onset NCSE and a previous stroke at a single institution undergoing CTP and EEG during symptoms. All patients underwent standard imaging including CT, CTP, CT angiograms and standard EEG within 30 min from hospital arrival. Age-/sex-matched NCSE without previous stroke cases and recurrent ischaemic stroke cases were included to test for accuracy of hyperperfusion rates.

RESULTS

Overall, 15 patients had a previous stroke and developed NCSE (mean age 78 years, 46.7% female). All patients had hyperperfusion on CTP imaging (mean onset-to-CTP 184 min). Only one case showed hyperperfusion limited to the previous stroke lesion, and one had a combination of lesional and peri-lesional hyperperfusion. All remaining cases (n = 13) had exclusive extra-lesional involvement. Five cases had multiple separated hyperperfused areas, and five had ipsilateral intra-thalamic hyperperfusion. No correlation emerged between onset-to-CTP timing and hyperperfusion (p value for CTP = 0.66, CBV = 0.28, MTT = 0.28, reverse Tmax = 0.66). Hyperperfusion was present in NCSE cases only and in none of age-/sex-matched ischaemic stroke cases (n = 18).

CONCLUSIONS

Hyperperfusion involves cortical areas external to the previous lesion site during NCSE, supporting the relevance of networks for the spatial evolution of epileptic activity and limited relevance of the lesion site for the propagation of the epileptiform activity.

Post-stroke epilepsy: From clinical predictors to possible mechanisms

BACKGROUND

Stroke is the most common cause of newly diagnosed epilepsy in the elderly, ahead of degenerative disorders, brain tumors, and head trauma. Stroke accounts for 30-50% of unprovoked seizures in patients aged ≥ 60 years. This review discusses the current understanding of epidemiology, risk factors, mechanisms, prevention, and treatment opportunities for post-stroke epilepsy (PSE).

METHODS

We performed a literature search in the PubMed and Cochrane Library databases. The keywords "stroke, epilepsy", "stroke, seizure", "post-stroke seizure", "post-stroke epilepsy" were used to identify the clinical and experimental articles on PSE. All resulting titles and abstracts were evaluated, and any relevant article was considered. The reference lists of all selected papers and reference lists of selected review papers were manually analyzed to find other potentially eligible articles.

RESULTS

PSE occurs in about 6% of stroke patients within several years after the event. The main risk factors are cortical lesion, initial stroke severity, young age and seizures in acute stroke period (early seizures, ES). Other risk factors, such as a cardioembolic mechanism or circulation territory involvement, remain debated. The role of ES as a risk factor of PSE could be underestimated especially in young age. Mechanism of epileptogenesis may involve gliosis scarring, alteration in synaptic plasticity, etc.; and ES may enhance these processes. Statins especially in the acute period of stroke are possible agents for PSE prevention presumably due to their anticonvulsant and neuroprotection effects. Antiepileptic drugs (AED) monotherapy is enough for seizure prevention in most cases of PSE; but no evidence was found for its efficiency against epileptic foci formation. The growing interest in PSE has led to a notable increase in the number of published articles each year. To aid in navigating this expanding body of literature, several tables are included in the manuscript.

CONCLUSION

Further studies are needed for better understanding of the pathophysiology of PSE and searching the prevention strategies.

Etiopathology, Clinical and Imaging Characteristics of Border Zone Strokes

Introduction

A border zone infarct (BI) is defined as an infarction that is localized to watersheds or border zones in the brain. BI is further classified into cortical border zone infarct (CBZ) and internal border zone infarct (IBZ). This study was conducted to explore the clinical and radiological characteristics of BI.

Materials and Method

The study was conducted on eligible 400 acute ischemic stroke patients out of which 52 BI patients (diagnosed by the radiologist on DWI MRI images), patients >18 yrs of age were selected and divided into two groups of IBZ and CBZ infarct patients. The degree of intracranial and extracranial stenosis and characteristics on clinical presentation were assessed. The data were collected and analyzed using SPSS version 20.0 software at significance level p-value <0.05.

Results

25% and 75% of CBZ and IBZ patients, respectively, had history of presyncope or syncope before stroke. On vascular evaluation, 3.9% and 51.9% were in MCA and ICA stenosis group, respectively. Evidence of cardio embolism was found in 17.3% of patients. 53.3% of CBZ and 53.8% of IBZ patients were in ICA stenosis group, and 6.7% of CBZ and 7.7% of IBZ patients were in MCA stenosis group, with a statistically insignificant relation (p-value >0.05).

Conclusion

Association of BI with events causing hypotension or hypovolemia is well-established in our study, association of BI with large vessel atherosclerosis is common, and its contribution to CBZ and IBZ seems to be equal.

Characteristics of the ischemic stroke patients whose seizures occur at stroke presentation at a single institution in Eastern China

PURPOSE

We compared clinical characteristics and outcomes of the early-onset seizure post-stroke patients who had seizures occurring at stroke presentation (SSP) with other patients without SSP at a single institution in Eastern China.

METHODS

We reviewed 20,947 ischemic stroke patients in our hospital electronic medical records system from January 2007 to December 2016. Among them, there were 91 (0.43%) patients with early-onset seizure post-stroke. Among these 91 patients, there were 35 (0.16%) SSP patients and another 56 (0.27%) were designated as non SSP patients because they also had early-onset seizure post-stroke, but without SSP. We compared the clinical presentations of the SSP patients with those of the non SSP patients including baseline stroke risk factors, and 10-year Kaplan-Meier death risk after their first stroke.

RESULTS

In the SSP patients, 25.7% of them presented with posterior circulation infarction, whereas only 12.5% of the non SSP patients had this condition (P<0.05). In contrast, 17.1% of the SSP patients were being treated with antiepileptic drugs at discharge whereas 37.5% of the non SSP patients received such treatment (P<0.05). The percentage of SSP patients with temporal lobe lesions was less than in non SSP patients (P<0.05). However, brain stem and thalamus lesions were more frequently seen in SSP patients than non in SSP patients (P<0.05). The risk factors for ischemic stroke including a history of hypertension, diabetes mellitus, hyperlipidemia and atrial fibrillation were the same in these two groups (P>0.05). In the SSP patients group, the 10-year risk of death was 36.9% after the initial seizure incident, and in the non SSP patients group, the 10-year death risk was 40.1%, but this difference between the two groups was not significant (P>0.05).

CONCLUSIONS

Ischemic stroke patients with SSP had some unique signs that included a higher incidence of posterior circulation infarction than non SSP patients.

Bilateral paramedian thalamic infarction initially presenting as a convulsive seizure

Bithalamic infarctions initially presenting as a convulsive seizure are rarely reported and, to our best knowledge, have never been reported in China. Here, we present a patient with convulsive seizure at the onset of bilateral paramedian thalamic infarction. The diffusion-weighted imaging revealed that the infarct area is supplied by Percheron artery. Associated with the relationship between seizure and centrencephalic system and reticular formation as previously reported, we suggest that seizure could be the onset symptom of paramedian thalamic infarction. Physicians should recognize this condition, because both seizure control and early ischemic stroke management are required.

Seizures and the neurosurgical intensive care unit

The cause of seizures in the neurosurgical intensive care unit (NICU) can be categorized as emanating from either a primary brain pathology or from physiologic derangements of critical care illness. Patients are typically treated with parenteral antiepileptic drugs. For early onset ICU seizures that are easily controlled, data support limited treatment. Late seizures have a more ominous risk for subsequent epilepsy and should be treated for extended periods of time or indefinitely. This review ends by examining the treatment algorithms for simple seizures and status epilepticus and the role newer antiepileptic use can play in the NICU.

Top of the basilar syndrome in a young adult initially presenting with a convulsive seizure

A 23-year-old man was admitted to our hospital due to loss of consciousness and a generalized convulsive seizure. He was diagnosed as having primary epilepsy and treated with antiepileptic drugs. Emergency CT scan of the head showed no abnormality. However, MRI scan of the head several days after admission revealed fresh infarctions caused by occlusion of the basilar artery, i.e., "top of the basilar" syndrome. This case indicates the need for precise differential diagnosis of convulsive seizure in an emergency situation. It should also be borne in mind that basilar occlusion with 'onset seizure' can occur even in young adults who have no risk factors for stroke.

Seizures and epilepsy in patients with a posterior circulation infarct

Seizures occur mainly in patients with cortical infarcts in the anterior circulation. Those related to a posterior circulation infarct (POCI) are considered rare. This study investigated the characteristics of patients with seizures related to a POCI. A total of 180 consecutive patients admitted with a POCI had a 2- to 7-year follow-up; 24 of them (13.6%) developed seizures. Vascular risk factors, etiology and extension of the infarct, degree of neurologic impairment, and outcome were compared in the patients with and without seizures. Complex partial type seizure was the most common presentation. Stroke characteristics were largely the same in the patients with and without seizures. History of a previous stroke was noted in 62.5% of the seizure group and in 17.9% of the nonseizure group (P < .001). Clinical outcome was worse in the seizure group (P = .004). The relative incidence of seizures in patients with a POCI was not lower than that in the overall stroke population. The high incidence of recurrent stroke is the main risk factor for seizures in patients with a POCI. The seizures themselves are responsible for the increased dependence rate.